Metagenomics Analysis of Gut Microbiota in a High Fat Diet–Induced Obesity Mouse Model Fed with (−)-Epigallocatechin 3-O-(3-O-Methyl) Gallate (EGCG3″Me)

Scope: (−)-Epigallocatechin 3-O-(3-O-methyl) gallate (EGCG3″Me) has been shown to have a modulatory effect on human intestinal microbiota, and the relationship between intestinal flora and obesity has attracted more and more attention recently. Here, the potential link between EGCG3″Me and gut microbiota composition, as well as the underlying mechanisms of the anti-obesity activity of EGCG3″Me are investigated. Methods and results: EGCG3″Me was prepared from oolong tea by column chromatography, and the influence of EGCG3″Me on intestinal microbiota was analyzed using a human-flora-associated high fat diet (HFD)-induced obesity mouse model by metagenomics. EGCG3″Me showed a weight reducing effect, ameliorated the HFD-induced gut dysbiosis, and significantly decreased the ratio of Firmicutes/Bacteroidetes. Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) database provided significant differences in differentially expressed genes in response to EGCG3″Me treatment. The results showed enrichment of genes involved in the biosynthesis of amino acids, the two-component system, ATP-binding cassette (ABC) transporters, purine metabolism, and carbon metabolism. Conclusion: An EGCG3″Me supplemented diet produces promising effects on gut microecology by enhancing beneficial microbial populations and by affecting metabolic pathways including amino acids biosynthesis, the two-component system, and ABC transporters, contributing to the improvement of host health.